The short answer
Usually, after a check. Might hold something you care about. Look inside before removing it.
What is it?
The source code of the Android framework for each API level, under ~/Library/Android/sdk/sources. Android Studio uses it only to let you read and step into framework code while debugging; builds never need it. Each level typically takes a few hundred megabytes.
Framework source code used only for browsing in the IDE. The newest is kept; others can be downloaded again.
What happens if you delete it?
Nothing downloads it again automatically. Android Studio offers to download sources when you open a framework class without them, or you can reinstall them from the SDK Manager.
How to remove it properly
In Android Studio, open Settings › Languages & Frameworks › Android SDK › SDK Platforms, tick Show Package Details and untick “Sources for Android” for old levels; or run sdkmanager --uninstall "sources;android-<level>" in Terminal (permanent).
Use the tool’s official command: sdkmanager --uninstall "<package>"
- MoreRoom keeps the newest 1 and suggests the older ones.
How MoreRoom helps
MoreRoom recognises this item and labels it “Review first”: it shows what’s inside, its size and last use, so you can decide. Nothing is removed without your say, and everything goes to the Trash first, with Undo.
When the tool is installed, MoreRoom runs its official command for you (sdkmanager --uninstall "<package>") instead of deleting files — and tells you that this step can’t be undone.
Frequently asked questions
Can I delete Android SDK sources on Mac?
Usually, after a check. Might hold something you care about. Look inside before removing it. Nothing downloads it again automatically. Android Studio offers to download sources when you open a framework class without them, or you can reinstall them from the SDK Manager.
Will Android SDK sources come back after I delete it?
Yes. Nothing downloads it again automatically. Android Studio offers to download sources when you open a framework class without them, or you can reinstall them from the SDK Manager.
How do I remove Android SDK sources properly?
In Android Studio, open Settings › Languages & Frameworks › Android SDK › SDK Platforms, tick Show Package Details and untick “Sources for Android” for old levels; or run sdkmanager --uninstall "sources;android-<level>" in Terminal (permanent).